Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: My 20 year old Japanese maple (Acer spp) did not return this year. I need help identifying what the problem is and how to resolve it. Pictures below show mushroom looking things growing on the tree. Not sure if it's the cause of the dieback. Thank you in advance!
MGCC Help Desk Response: As you have already recognized, the presence of the mushrooms on the trunk of your Japanese Maple tree is not a good development. It indicates that a fungus has somehow entered the tree. Typically, such fungi enter a tree's system either through the roots or through a wound on the tree or its roots. Wounds can be caused by such things as a nick by a lawn mower or “weed eater” cutter, excavations or poor pruning practices. Fungi can also enter the tree if a “root rot” disease develops. Once the fungus has entered the tree's interior tissue, it breaks down wood fibers, releasing nutrients needed to feed the fungus. After mushrooms become visible, the attack is well underway, and the fungus has begun reproducing through spores in or on the mushrooms.
When mushrooms are present on the main trunk of the tree as appears to be the case with your tree, there is not much hope that the tree can be saved. The breakdown of the tree's internal wood fibers to feed the fungus may weaken the tree structurally and if the problems has developed from a root rot problem, the roots may be weak and less able to support the tree. For these reasons, you may want to consider removing the tree.
Without knowing more about the history of your tree and the symptoms of earlier declines to the tree's health that may have been evident in prior growing seasons, we are unable to determine the precise cause of the decline of your tree. You may be able to learn more about the possible causes of the tree's decline at this University of California website: http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/maple.html The website lists common disease problems that can affect Japanese Maple. We suggest that you look at the links for “root and crown rot” and for “wood decay” and consider whether they describe earlier signs or symptoms of a problem that you may have noticed in past growing seasons.
The abundance of pale, honey colored mushrooms shown in your photos suggest another possible fungal root disease not mentioned on the UC website referenced above. A fungus known as Armillaria mellea is the cause of Armillaria root rot. Early symptoms you might have observed if this fungi is the cause of the problem include reduced growth, yellowish leaves and dieback of twigs and branches. The development of the pale colored mushrooms around the base of the tree or the surrounding ground is a later development in the progress of the disease. If you suspect this fungus might be the cause of the tree's decline, you may want to try to confirm the diagnosis by looking for the presence of white mycelial fans between the bark and the underlying sapwood of the tree. This UC website has additional information about Armillaria root rot and includes a photo showing the white mycelial fan structures that underlie the bark: http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/armillariartrot.html
Keep in mind that if the source of the fungal disease was in your soil, the fungal spores may remain in the soil and could potentially affect the roots of a replacement soil. For this reason, it would be a good idea to try to determine what disease was present in your tree. You might want to consider hiring an arborist to examine the tree and confirm what caused the problem. The arborist might also be able to provide a crew to remove the tree and give you some guidance on steps to take to avoid having a replacement tree develop the same problems. Here is a link to the International Society of Arboriculture (ISA) website. It has a search feature that allows you to find a certified arborist based on where you live. https://www.treesaregood.org/findanarborist
I hope that you find this information to be helpful. Please contact us again if you have further questions.
UC Master Gardener Program of Contra Costa County (tkl)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer our gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523, although we will be moving this spring. We will notify you if/when that occurs. We can also be reached via telephone: (925)646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/)
/table>Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Help Desk Response: Thank you for emailing the photos of the spots on your blueberry leaves. While we are unable to specifically identify the disease with certainty, it is highly likely that the spots are caused by a type of Anthracnose leaf spot fungus.
This and most other fungus diseases thrive in cool wet weather such as we have had this past year. The Anthracnose fungus has been identified on blueberries by researchers at the University of Oregon. The University of California recommends a number of measures that can be undertaken to control fungus. In general, it is recommended that you select resistant varieties and planting should be in the full sun. Other recommended practices for reducing fungal diseases include the following:
- Prune diseased growth as it appears.
- Provide drip irrigation if possible, otherwise irrigate in the early morning using mini-sprinklers.
- Avoid over fertilizing.
- Prune in the winter to increase air circulation.
- Once you have cleaned up diseased material from the plant and soil, place a generous amount (3 inches deep) of mulch on the soil below the plant canopy. This will help trap fungal spores so they don't splash up and re-infect the plant.
Hopefully implementing these practices and the onset of dryer, hotter weather will reduce the spread and minimize damage caused by the fungus.
There are also a number of additional recommendations for how to plant blueberries in a manner that will increase the plant health and resistance to stressors including diseases. These include:
- Select a variety bred to do well in California soil and known to do well in hot areas. These include Emerald, Jewel and Star.
- Plant in acidic (pH of 4.5-5.5), well-drained soil.
Blueberries belong to the Ericaceae family, which also includes other acid-loving plants such as azalea and rhododendrons . These plants need higher acidity to uptake needed nutrients. Contra Costa soils are generally slightly acidic to moderately alkaline. You can test your soil pH using a kit purchased from your local nursery. If you need to increase acidity, amend the soil six months prior to planting with 6-12 lbs. of aluminum sulfate per 100 square feet of garden. This will increase acidity by one pH unit (from 6 to 5). Another option is to plant them in raised beds (8-18 inches high by 3-4 feet wide) or a large pot. This allows you to more easily manage the soil pH and drainage. - Plant in a location where there is minimal frost and wind.
- Add mulch, which is usually slightly acidic and releases beneficial elements gradually and supports beneficial microbial organisms. Liquid fertilizers can be too strong. If using, apply four weeks after planting with a 10-10-10 mixture and reduce the amount recommended on the label. If using organic fertilizer apply one pound of blood, feather, or fish meal for each plant.
- Irrigate to maintain moist but not wet soil as blueberry roots are vulnerable to root rot.
- Hand weed to avoid damaging fragile surface roots.
If you would like additional information about blueberry varieties and growing tips, you can find it at: http://ucanr.edu/sites/gardenweb/berries/blueberries/
In addition, the UC Master Gardener Program of Contra Costa County is holding a program on Successfully Growing Blueberries at "Our Garden" on May 17th from 9am to noon. The main program will be presented at 10am by Kathy Echols, long-time DVC horticulture instructor. Our Garden is located in Walnut Creek at the corner of N. Wiget Lane and Shadelands Drive.
Thank you for contacting our UC Master Gardener Program. Please feel free to re-contact us with further questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (NPH)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).
/span>Advice for the Home Gardener from the Help Desk of the
Master Gardener Program of Contra Costa County
Home Gardener's Request: Here are some recent pictures this spring of similarly affected peach trees in the County. Several home gardeners with peach trees affected with this problem have recently asked the Help Desk for any information about what this is and how to treat it.
MGCC's Help Desk Response: Thank you for the questions to the Master Gardener Program's Help Desk with your problems with your peach trees. Based upon our review, it looks like you have a very common fungus called Peach Leaf Curl. There are UC documents with links below that I urge you to read. They will help you care for your peach trees year-round which should help you control this disease.
Unfortunately, there is little you can do right now. Some pick off the distorted leaves, but there is little evidence that this improves control. The tree needs to be sprayed with a copper fungicide in the fall and again in late winter/early spring before buds break. The linked "pnleafcurl.pdf" article below will give you more specific information about proper control methods and products.
For example, it says: "Peach leaf curl, also known as leaf curl, is a disease caused by the fungus Taphrina deformans. Peach leaf curl affects the blossoms, fruit, leaves, and shoots of peaches, ornamental flowering peaches, and nectarines, and is one of the most common disease problems for backyard gardeners growing these trees.
The distorted, reddened foliage that it causes is easily seen in spring. When severe, the disease can reduce fruit production substantially...Normally, diseased leaves fall off within a few weeks and are replaced by new, healthy leaves, unless it is rainy.
If a tree is severely affected with peach leaf curl this can stunt its growth, so consider thinning fruit later in the season. Pruning in fall prior to applying any fungicides can reduce spore numbers overwintering on the tree and reduce the amount of fungicide needed. If leaf curl symptoms occurred on your trees in spring, be sure to treat the following fall and/or winter to prevent more serious losses the following year. When using pesticides, always read and follow the label for usage, rates, toxicity, and proper disposal. Proper protective clothing and gear including goggles should be used when handling any pesticides" (Emphasis mine).
I hope this information helps you get your leaf curl fungus problem under control. Your pictures do not appear to show a heavy infestation, so taking proper control methods this fall and next spring before the leaves open should prove effective.
http://homeorchard.ucdavis.edu/7261.pdf
http://ipm.ucanr.edu/PDF/PESTNOTES/pnleafcurl.pdf
Help Desk of the Master Gardener Program of Contra Costa County (TDT)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).
Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County
MGCC Help Desk Request:I am located in Central County. I am having issues with my lemon tree. I have attached some photos. I was hoping you could give me some advice.
I have never sprayed pesticides. I am hoping for a more organic solution to the issues. I know it might not be possible.
I have not fertilized it this year. It is on our sprinkler system so it gets water daily. Some of the leafs have spiderweb looking substance under the leafs. Some leafs are yellow. I have also noticed the spikes are very large. Thank you so much for your help.
MGCC Help Desk Response: Thank you for contacting UC Master Gardener Program with your lemon tree questions and for sending the photos. The symptoms you are seeing could be the result of various minor problems that occur on citrus. The curled leaves show signs of citrus leaf miner. Citrus leaf miners are moth larvae that create shallow tunnels in young leaves. They can distort the leaves but are generally not harmful to the tree. You are probably seeing the end result of leaf miner damage that was done previously. For more information on citrus leaf miners, see: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74137.html.
We are not sure about the spiderweb type substance. It could be from an insect, e.g., whiteflies, but if so you should also find sticky areas on the leaves. Also, any pictures of the insect would be helpful. It is also possible that there are spiders on your tree. If that is the case, I would not worry. If you want the spider identified, see if you can get a photo and we will try to identify it.
The fruits look like they may have been damaged by the thorns which you indicated are very large. That would happen if the fruits were rubbing against the thorns. Is that possible? If not, another possibility would be herbicide damage. Is it possible that herbicides were used anywhere near the citrus tree? Even your neighbors? Make sure you remove the damaged fruits from the tree before we have any more rain. The damaged areas provide an opening for fungi and other diseases to get into the tree. Also, large thorns might indicate that the branch is a juvenile branch or is coming from below the graft, the "bump" near the bottom of the trunk. If from below the graft, you should consider removing that branch as it probably will not produce edible fruit.
The spots on the leaves may be from a fungus. The fungus may be the result of the watering, especially if the sprinkler system is putting water on the leaves. Make sure that the sprinkler is set low and also make sure that the sprinklers are not dampening the tree trunk. Wet tree trunks can lead to root or crown rot from fungus growing around the roots and crown (where the roots and trunk meet). Root and crown rots are serious diseases that are difficult to treat and can ultimately kill the tree.
The daily sprinkling may also be causing other problems for the overall health of your tree. Daily watering might not be supplying the citrus with enough water. Citrus, like most trees, do best with less frequent, and deep watering to promote stronger roots. To give you an example of how infrequent the watering should be, watering in the heat of summer should be done about every seven to ten days. This would be for citrus planted in the ground and with several inches of mulch under the tree out to drip line. In a pot you would need more frequent watering as they dry out faster. If other plants on your irrigation system need frequent watering, you should consider setting up a separate irrigation system on a different timer for the lemon. For more information on watering citrus, see: http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/citruswatering.html.
You mentioned that you had not fertilized the tree this year. Yellow leaves are a common sign of a lack of nitrogen. Citrus trees require regular fertilization, especially with nitrogen. The fertilizer should be applied in January or February (prior to bloom) with a second application in May and perhaps a third in June. This link has more information on fertilizing citrus: http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/citfertilization.html.
Finally, I thought that you might be interested in this general write-up on growing citrus in Contra Costa County: http://ucanr.edu/blogs/slomggarden/blogfiles/4260.pdf
Please let us know if you have any remaining questions. You are also welcome to bring plant samples into our office if you want more information. We are open Monday to Thursday, 9am to 12 noon.
Good luck with your lemon tree..
Help Desk of the UC Master Gardener Program of Contra Costa County (ECS)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).
Advice from the Help Desk of the
UC Master Gardeners Program of Contra Costa
UCMGCC Help Desk Response: Thank you for sending in the photo of your Toyon. It was very helpful.
Based on the picture, it looks like your Toyon has a mild form of scab. Scab is caused by various types of fungus. Scab appears first as pale or yellow dots on leaves. Affected leaves can twist or pucker. At more advanced stages, which you do not seem to have, you would see dark, olive-colored spots on the leaves. You could also find soft, velvety spots on the undersides of the leaves.
Scab is spread through the air, and more importantly by splashing water. Hot dry weather usually slows the development of scab. The disease is most active during spring rains.
To limit the spread of the disease, remove and dispose in your garbage waste bin of any fallen leaves from the plant. Avoid any overhead watering. You may also want to prune the plant to open up the canopy to allow more air on the leaves.
For more information on scab, see http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/scab.html
For information on pruning, see http://extension.oregonstate.edu/linn/sites/default/files/pruning_pub_handout2012.pdf
Note that there are two basic types of pruning cuts: thinning (which remove entire branches) and heading (which shorten branches). You want to focus on thinning cuts which reduce plant density. See page 2 of the document for the complete descriptions of the differences.
Please let us know if you have further questions.
Good luck with your Toyon.
Help Desk of the UC Master Gardener Program of Contra Costa (ECS)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).